This invention relates to a method of producing an agent for treatment of cellulose fabrics.
As an agent for treatment of cellulose fabrics, phosphoryl amide compounds have been used hitherto. The phosphoryl amide compounds are obtained by a reaction of phosphorus oxychloride and ammonia. For obtaining a phosphoryl amide compound by this reaction, the following methods have hitherto been adopted:
(1) a method for addition of phosphorus oxychloride into liquid ammonia;
(2) a method for addition of ammonia to a solution of phosphorus oxychloride in a halogenated hydrocarbon (U.S. Pat. No. 2,661,311);
(3) a method for addition of ammonia to a solution of phosphorus oxychloride in a hydrocarbon; and
(4) a method for addition of phosphorus oxychloride to aqueous ammonia.
However, Method (1) mentioned above is disadvantageous in that the energy necessary for maintaining a low temperature is costly and the method requires to use a special apparatus. Method (2) is disadvantageous in that the insoluble intermediate is deposited in the system and necessitates a great power for its stirring and that, since the three chlorine groups of phosphorus oxychloride cannot completely be converted to amino group, the product contains unreacted chlorine groups and such a product is unsatisfactory for use as an agent for treatment of cellulose fabric.
Method (3) has the same fault as that of Method (2), and further it has problems that the hydrocarbon used as a solvent can partially be chlorinated and, since the hydrocarbon has a low flash point, there is a danger of ignition in the process of the reaction.
Method (4) has a problem that, since phosphorus oxychloride competitively reacts with water and ammonia, it is partially hydrolyzed to lower the yield of the intended product and a problem that a water-insoluble intermediate is formed. Further, the phosphoryl amide compound present in the resulting aqueous solution slowly undergoes hydrolysis in the process of concentration at elevated temperature or in the course of storage and transforms into a substance unsuitable as an agent for treatment of cellulose fabrics.